air pressure and mems in ADIS16445

Very good IMU ADIS16445AMLZ is not equipped with pressure sensor, so i had to use the external sensor. Also i used the external accelerometer to backup if the Z acc will go over range. Once i got the different meanings from these accelerometers. It was at the same time when sharp but small pressure wave entered the compartment.

We do have quite a bit of test data to suggest that pressure, by itself, will not cause 1g of error in the acceleration measurements. Rapid change in pressure is difficult for us to test, but I would hesitate to assume that this is only a sensor response to change in pressure. I would wonder if the change in pressure was also accompanied by transient mechanical motion through the structure, cause different accelerations at the different accelerometer locations.

We do have quite a bit of test data to suggest that pressure, by itself, will not cause 1g of error in the acceleration measurements. Rapid change in pressure is difficult for us to test, but I would hesitate to assume that this is only a sensor response to change in pressure. I would wonder if the change in pressure was also accompanied by transient mechanical motion through the structure, cause different accelerations at the different accelerometer locations.

The structure is rigid enough - it can be described as a plastic tube 4 inch in diameter and 1/16 inch wall thickness. Both sensors were attached to the compartment covers 6 inches apart, made of the same plastic and the same thickness.

Okay, i need to find another root of the difference in accelerometers data.

I also have lateral accelerometer records, but they differ exactly as it should be according to bandwidth difference.

Thank you for the additional information. I shared this with a colleague, but I am not sure if and when they will be available to offer more details. He is in pretty high demand, but I thought it would be worth a try.

I understand completely. My colleague was able to take a quick look and offered that he didn't see any behavior that he could correlate to the pressure change, but that it would be nice to see all of the inertial data (gyroscopes and accelerometers) in a manner that is time correlated to other data (extra accelerometer, pressure, etc). Hope that helps...